This report shows how air quality in the People's Republic of China's fast-growing Beijing-Tianjin-Hebei industrial hub has deteriorated and presents an integrated, cost-effective model to reduce emissions. Analyzing the costs and benefits of different scenarios, it sets out a modeling framework and shows how adapting policies to tackle emissions and improve air quality can help boost the region's development, environment, and public well-being. It shows how increasing energy efficiency and reducing fossil fuel consumption can improve air quality and help the PRC meet its commitment to achieve carbon neutrality before 2060.